The present invention relates to resonant standing wave modulators for optical radiation and, more particularly, to such a modulator which provides coupling of microwave energy to a beam of optical radiation with high efficiency.
Resonant standing wave microwave optical modulators are becoming increasingly important for many different high energy applications. For example, they are finding significant use as part of spectroscopic instruments and for laser mode locking. An optical modulator is a device for either phase or intensity (amplitude) modulating a beam of optical radiation. Most devices of this nature modulate the phase of the optical radiation and some comprise a block of a monocrystalline electro-optic material within a microwave cavity. The microwave cavity supports the modulating energy, and the block of crystalline material applies the same to the optical radiation. In this connection, the microwave energy typically is phase matched or quasi-phase matched, with the optical radiation to be modulated.
In general, modulators of the above type provided in the past have not been very efficient, i.e., power required to achieve a satisfactory degree of modulation of a beam of optical radiation, has been relatively high. These modulators have had a relatively low Q (quality factor). Efficiency is directly related to the Q of a modulator.